66 On Oil and Oil-gas. 
a little, but it isa very slow operation., A 
pint of oil was about + part distilled in two 
or three hours’ constant ebullition. The boil- 
ing at Jast was as steady and tranquil as at 
first; and the receiver and retort were free 
from. cloudiness. 
A quantity of acid fumes were discharged 
and filled the small room where the above 
process was carried on, so as to affect the 
throat. and to. feel very ‘suffocating. Proba- 
bly these fumes were the sebacic acid mixed 
with carbonic acid; they did not appear to be 
at all combustible. 
Whale oil,is considerably altered by distil- 
lation, both in specific gravity and in its other 
properties. . I did not notice the specific gra- 
vity of the above before distillation; but this 
species of oil is usually ,92 nearly. . After dis- 
tillation the residuum had the specific gravity 
394; whereas the distilled part had the specific 
gravity ,85, the first produce or watery part 
being thrown away. ‘The residuary oil is 
black and less fluid than.at first; the distilled 
part is more fluid than at first. 
I found the specific gravity of old whale oil 
that had been heated continually for 35 days 
to 360°, but had never been boiled, to be ,960. 
It nearly resembled the residuary oil in the 
above-mentioned distillation. 
